Scientists at The Scripps Research Institute (TSRI) have found that an enzyme best known for its fundamental role in building proteins has a second major function: to protect DNA during times of cellular stress.

For decades, researchers have used petri dishes to study cell movement. These classic tissue culture tools, however, only permit two-dimensional movement, very different from the three-dimensional movements that cells make ...

Recently, O-linked N-acetylglucosamine (O-GlcNAc), a sugar ring that reversibly modifies proteins inside the cell nucleus and cytoplasm in a process known as O-GlcNAcylation, has been revealed to be a key regulator of cell ...

DNA carries out its activities "diluted" in the cell nucleus. In this state it synthesises proteins and, even though it looks like a messy tangle of thread, in actual fact its structure is governed by precise rules that are ...

Researchers have successfully isolated and sequenced the entire messenger RNA – the "genetic photocopies" – contained in the nucleus of a single brain cell. This research, published in the journal Proceedings of the National ...

By using a new analysis method, researchers at Karolinska Institutet and Science for Life Laboratory (SciLifeLab) in Sweden have found close to one hundred novel human gene regions that code for proteins. A number of these ...

(Phys.org) —The effects of gravity are relevant when building houses or flying airplanes, but biologists have generally accepted that the average cell is too small for gravity to play a role in how it is built or behaves. ...

Cell biologists and chemists from the University of Zurich reveal how viral DNA traffics in human cells. They have developed a new method to generate virus particles containing labeled viral DNA genomes. This allowed them ...

New research from the University of California, Davis, shows that the tiny proportion of a cell's DNA that is located outside the cell nucleus has a disproportionately large effect on a cell's metabolism. The work, with the ...

Certain parts of DNA are highly mobile and their dynamic motion participates in controlling gene expression. The research team working under Maria-Elena Torres-Padilla, an Inserm research director at the Institute of Genetics ...

Cell nucleus

In cell biology, the nucleus (pl. nuclei; from Latin nucleus or nuculeus, or kernel), also sometimes referred to as the "control center", is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome. The function of the nucleus is to maintain the integrity of these genes and to control the activities of the cell by regulating gene expression--the nucleus is therefore the control center of the cell.

The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and separates its contents from the cellular cytoplasm, and the nuclear lamina, a meshwork within the nucleus that adds mechanical support, much like the cytoskeleton supports the cell as a whole. Because the nuclear membrane is impermeable to most molecules, nuclear pores are required to allow movement of molecules across the envelope. These pores cross both of the membranes, providing a channel that allows free movement of small molecules and ions. The movement of larger molecules such as proteins is carefully controlled, and requires active transport regulated by carrier proteins. Nuclear transport is crucial to cell function, as movement through the pores is required for both gene expression and chromosomal maintenance.

Although the interior of the nucleus does not contain any membrane-bound subcompartments, its contents are not uniform, and a number of subnuclear bodies exist, made up of unique proteins, RNA molecules, and particular parts of the chromosomes. The best known of these is the nucleolus, which is mainly involved in the assembly of ribosomes. After being produced in the nucleolus, ribosomes are exported to the cytoplasm where they translate mRNA.